Indirect water-heating apparatus



April 15 1924. 1,490,860

c. SMITH ET AL INDIRECT WATER HEATING APPARATUS Filed Feb. 17, I922Berzram C. [fa/p By Httome];

Patented Apr. 15, 1924.

, STATES PATENT oFFicE.

CHETWOOD SMITH, F WORCESTER, AND BERTRAM G. HARPER, OF BOSTON, MASSA-CHUSETTS, ASSIGNORS TO STACK HEATER COMPANY, OF BOSTON, MASSACHUSETTS,

A CUORATION OF MASSACHUSETTS.

INDIRECT WATER- ENG P TUS.

v To all whom it may concern:

Be it known that we, Cm'rwoon SMITH and BnRTRArZt C. HARPER, citizens ofthe United States, said SMITH residing at 5 Worcester, in the county ofWorcester and State of Massachusetts, said HARPER residing at Boston,county of Sufiolk, and State of Massachusetts, have invented a new anduseful Indirect Water-Heating Apparatus,

mof which the following is a specification.

' lihis invention relates to' improvements in indirect Water heatingapparatus such as is umd in hot water storage and supply systems.Similar devices nowcommonly in use are efl'ective for heating the watersupply under normal conditions of operation, but having a marked tendento become overheated at times of reduced emand, particularly, ifassociated with main heaters used tor-other put.

it is the neral object of our invention to improve't e construction ofsuch heating apparatus, particularly by provig improved devices forpreventing or relieving overheatin and for maintaining an adequate suppy of water in the indirect heatin system.

nether object of our invention is to provide for proper disposal of thesteam or water, it any is discharged from the indirect system by reasonof overheating.

. @ur invention further relates to arrange ments and combinations ofparts which will he hereinafter described and more particularly pointedout in the appended claims.

A preferred form of our invention is shown in the drawing which is afront elevation of our improved apparatus, parts thereof being shown'insection. v

Referring to the drawing, we have shown a hot water storage tank 10which ay be (ill of any usual construction and which is provided withthe usual cold water supply pipe l1 and hot water discharge pipe 12. The24 storage tank 10 is connected by upper and lower pipes 13 and is tothe opposite ends of a coil or nest of i t 15 contained within a casing16 and orming therewith an i indirect Water heater.

A main heater 20 is shown in the drawings and, in this particular w .51| m. of our invention, this heater is inthe form of a hot air furnace.A heating unit 21 extends into the fire box of the main heater 20 and isconnected b upper and lower pipes 22 and 23- with the indirect heatercasin l6. A water supplytank 24 is connected y a pipe 25 to the lowerconnection .23 between the heating unit and the indirect heater.

The tank 24 is open to the atmosphere and the water level therein iscontrolled by a float valve of any usual form.

A vent pipe 26 extends upward from the upper connection 22 and isprovided with an outlet 27 controlled by a. valve 28. A pipe 29 extendsfrom the pipe 26 to the heater 20 where a branch pipe 30 extends 'intothe ash pit of the heater and isprovided with a valve 31. A secondbranch pipe 32 controlled by a valve 34: extends into the water box 33commonly provided in hot air furnaces for moistening the air passingthrough the furnace. A safety valve 35 of ang usual design is alsopreferably connecte to the pi 26. y

be open at all times and the safety valve 35 is required for protectiononly in the event that all of these valves are accidentally closed atthe same time.

Assuming that the valve 28 only is open, the pipe 26 will be filled withwater to the level of the water in the supply tank 24:, hut will permitthe discharge of steam from the indirect heating system should the samebecome overheated. This condition not infrequently arises, particularlyin house heat ing apparatus on occasions when the main heater 20 isbeing heavily fired while the demand for hot water from the tank 10 isat the sametime reduced. Should the water in the indirect system becomeoverheated, the steam is discharged from the outlet 27 and any waterdischarged therewith is immediately replaced from the supply tank lt issometimes objectionable to discharge this steam and water mixturedirectly into the atmosphere of the cellar or other space in which theheater is located. To avoid this objection, we have provided the pipe29- and its branch pipes 30 and 32. en the pipe 30-is open, the steam orwater from the vent pipe 26 is discharged into the ash pit of the,heater. The steam passes upward through the fuel bed and may he ofactual' nection is sufiicient in whic advantage in the process ofcombustion. If the steam and water is discharged through the pipe 32into the water box 33, the temsystem in which all three of these reliefconnections are provided, in actual use it will.

be usually found that a sin 1e selected concase no shutoif valve orsafety valve is necessary.

Certain of the advantages of ourv invention may be obtained by the useof the sup- 7 ply tank 24 and its connecting pipe 25 only,

omitting the vent pipe 26. In this 8.36, the excess of pressure causedby the overheating of the unit 21 is to some extent relieved through thepipe 25. Satisfacto operation is, however, much improved by t e additionof the vent pipe 26 connecting into the upper ipe 22. v Y

will be evident that changes and modifications can be made therein by.those skilled aving thus described our invention, it

in the art within the spirit and scope of our invention as set forth inthe claims, and we do not wish to be otherwise limited to the detailsherein disclosed but what we claim is:

1. Water heating apparatus comprising a storage tank, an indirect waterheater therefor, a main heater, a heating unit therein, upper and lowerconnections forming with said indirect heater and said unit an indirectheating system, a water supply, and a vent pipe for said systemdischarging into the ash pit of said main heater.

2. Water heating apparatus comprising a storage tank, an indirect waterheater therefor, a main heater having a water box, a heatin unit in saidmain heater, connections f drming with said indirect heater and saidheating unit an indirect heatng system, and a vent pipe for said system,said vent pipe discharging into said water box.

In testimony whereof we have hereunto aflixed our signatures.

CHETWOOD SMITH. BERTRAM C. HARPER;

